Would it be possible to have a nightly build Rust compiler for convenience (faster build cycle, auto-update) and a dev version of Rust cloned from GitHub for experimentation
You also don't need to install your development version. You could just make symlink from somewhere in your $PATH to the rustc binary that lives somewhere inside the source tree/build directory, the compiler will find its dynamically linked dependencies and it will emit binaries that know about that path too (if even dynamically linked).